The applicant?s long-term interests are to improve the quality and efficiency of care for patients with critical illness by conducting outcomes, health services and health policy research in this field. A specific, current interest is patients with prolonged mechanical ventilation following acute respiratory failure. These patients appear to have a high short-term mortality rate, require intensive technical and personnel support, and are increasingly receiving care in non-ICU settings, such as long-term acute care facilities. Existing data on the incidence, patient and clinical characteristics, and clinical outcomes (e.g. duration of illness and mortality) are limited by such factors as selection bias and small study size. No data exist on the extent to which non-ICU settings are used to care for these patients, and limited information exists on determinants of long-term care hospital utilization or on comparative outcomes for this model of care. This proposal will utilize national Medicare data to define the epidemiology, clinical outcomes and predictors of these outcomes for elderly Medicare patients with prolonged mechanical ventilation. Also using this national database, long-term acute care hospital utilization, associated patient and clinical characteristics, and its impact on clinical outcomes will be explored. Focus group and physician survey work will be employed to determine at a more detailed level factors associated with utilization of long-term care hospitals, including physician attitudes and perceptions of quality of care.